[unreadable] [unreadable] Transcription factors (TFs) are cellular proteins responsible for controlling gene expression. Understanding the mechanism underlying the activation of these proteins will help us dissect cellular signaling pathways and determine the relationship between transcription activation and human diseases. Monitoring the activities of transcription factors in vivo usually relies on a genetic reporter construct that contains a cis-element corresponding to a specific transcription factor, a minimal promoter, and a reporter gene. When the transcription factor is activated, it binds to the cis-element and induces the expression of the reporter gene. Through enzymatic analysis of the reporter, the activity of the transcription factor can therefore be measured, and furthermore the level of transcriptional induction can be determined by comparison of control and treated cells. As the reporter is a single molecule, each assay can determine only one transcription factor's activity. Consequently, if multiple transcription factors need to be measured, the work will be tedious and time-consuming because it will involve multiple transfections and a repeat of the same assay over and over again. In the study, we propose to use a series of tag sequences as the reporter. We will create a library of reporter constructs, each containing a cis-element and a unique genetic tag sequence. The expression of reporter tags will be induced if their corresponding transcription factors are activated and bound to the cis-elements in host cells. The expressed tag sequences can then be determined with an array assay. With this technology, the simultaneous activation of multiple transcription factors in signal transduction pathways in vivo can be monitored at once. [unreadable] [unreadable]